"Economists are not without knowledge. We know that restrictions on trade tend to help narrow interests at the expense of broader prosperity. We know that market prices are important for coordinating specialization and division of labor in a complex economy. We know that the profit incentive promotes the introduction of improved products and processes, and that our high level of well-being results from the cumulative effect of such improvements. We know that government control over prices and production, as in communist countries, leads to inefficiency and corruption. We know that the laws of supply and demand tend to frustrate efforts to make goods more "affordable" by subsidizing them or to lower "costs" by fixing prices.

"But policymakers have goals that go far beyond or run counter to such basic principles. They want to steer the economy using fiscal stimulus. They want to shape complex and important markets, including those of health insurance and home mortgages. It is doubtful that the effectiveness of economic theory is equal to such tasks.

"Most scholarly research in economics is ultimately motivated by the unrealistic goal of providing effective theory to implement such technocratic objectives. But the resulting economic theory cannot be applied with the same confidence as Newtonian physics. Even worse is the fact that economists, unlike physicists, are not clear about the limits of the effectiveness of their theories. In short, when it comes to effective theory, economists promise more than they can deliver. ..."

"There is a very real possibility that over the next 20 years academic economics will congeal into a discipline, like sociology today, which is definitively shaped by an ideologically driven point of view. Among highly educated people, ideological polarization is increasing. Economists have always had their biases about which sorts of theories seemed reasonable; some of these biases are idiosyncratic, as when one economist is inclined to believe that labor demand responds very little to a change in wage rates and another is inclined to believe that labor demand responds a great deal. But going forward, biases are likely to increasingly be driven by political viewpoints rather than by other considerations.

"This will be evident in beliefs of economists that are politically consistent but analytically contradictory. For example, it is politically consistent for someone on the left to believe that a rise in the minimum wage would not reduce hiring and also that more immigration would not depress wages. Analytically, however, these are opposite views. The minimum-wage increase will not reduce hiring if one treats labor demand as highly inelastic (so that a small change in hiring will be associated with a given change in wages). Increased immigration will not depress wages if one treats labor demand as highly elastic (so that a large change in hiring will be associated with a given change in wages). I think we are already starting to see economists opt for political consistency at the expense of analytical consistency.

"This more political profession is very likely to point toward the left. Economists are part of an academic community in which peer pressure and community values push left. It is inevitable that the social life of an academic is going to involve interacting with people from other disciplines who are overwhelmingly on the left. This makes it uncomfortable on campus to espouse the free-market views that one used to hear from conservatives like Milton Friedman. There are signs that the momentum within the profession is toward the left. ...

"Young economists who employ pluralistic methods to study problems are admired rather than marginalized, as they were in 1980. But economists who question the wisdom of interventionist economic policies seem headed toward the fringes of the profession.
In this respect, the barriers to effective theory in economics are different and perhaps more worrisome than was the case in 1980. The contemporary state of economic theory reflects a broader crisis in the social sciences and a deepening cleavage between the college campus and the rest of society."

It's wise to be skeptical about claims of economists. It's also wise to be skeptical about claims of noneconomists. It's true that economists are often not clear about the limits on the effectiveness of their theories. In my experience, noneconomists are typically even less clear about limits on the effectiveness of their theories--indeed, noneconomists are often loathe to acknowledge that their theories have any limitations at all.

As I try to piece together my own views on these topics, I'm reminded of some comments from Herbert Stein, who was an economist in many positions in Washington, DC for more than 50 years (from his 1995 collection of essays, On the Other Hand - Essays on Economics, Economists, and Politics). Here's his comment comparing the knowledge of economists and non-economists (p. 78)

"In the preface to a book of mine called Washington Bedtime Stories, I summed up two main lessons derived from more than fifty years in Washington as a civil servant, researcher, presidential adviser, observer, and commentator:

Economists do not know very much.

Other people, including the politicians who make economic policy, know even less about economics than economists do.”

Stein also had some pungent comments on how people are affected by their preexisting political views (p. 248 of the same book):

"I think that most people—even those who read the editorial and op-ed pages—do not want to encounter opposing views. They want a good expression and confirmation of the views they have, or the views they would have if they thought about the subject. I can see that tendency in myself. I rarely read the columnists I know I am going to disagree with. Life is too short. ... Probably almost all readers of magazines with pronounced ideological or partisan slants share those slants. They want to be massaged, not informed.

"In all my years of writing opinion pieces, I don't think I have ever received a letter from a reader who said that I had changed his mind. I get some letters--a few--from readers who say they agree with me. Many of them say not only that they agree with me but that they had had the same thought ten years ago and had written a fifty-page essay about it that they would like my help in getting published. Some write to disagree with me, often violently. But I don't remember any saying that I had changed his mind. "

And here's one more shot of Stein (from pp. 1-2 of the same book):

"An old saying goes that whoever is not a Socialist when young has no heart and whoever is still a Socialist when old has no head. I would say that whoever is not a liberal when young has no heart, whoever is not a conservative when middle-aged has no head, and whoever is still either a liberal or a conservative at age seventy-eight has no sense of humor. Obviously, orthodox certainty on matters about which there can be so little certitude must eventually be seen as only amusing."

For myself, I don't have much problem when politicians or actual real-world people choose to read economists with whom they basically agree. Choosing the experts who fit with your predispositions is a very human thing to do, and asking nonspecialists to arbitrate disputes between specialists is difficult. But here's the kicker: When you have chosen the experts with whom you basically agree, a basic degree of intellectual consistency means that you need to listen to all that they say--including possibly unwelcome warnings about limitations, problems of implementation, other implications, and so on. So choose your expert, by all means, but then also be predisposed to follow or at least to acknowledge both the welcome and unwelcome parts of what that expert has to say.